The proposed research will study the effects of membrane lipid modification on the functional properties of neuronal cells using continuous culture cell lines of neuronal origin. The work will involve the neuroblastom X glioma hybrid, NG108-15, and the pheochromocytoma clone PC12. The membrane lipid modifications will include changes in fatty acid composition, polar head group composition of the phospholipids and changes in cholesterol content. The cell functions to be examined will include membrane-bound enzyme activities, the uptake and release of neurotransmitters and neurotransmitter precursors, receptor binding, coupling between receptors and effectors, and electrical properties of the cells.